Preliminary results of a longitudinal study of changes in cognitive function in breast cancer patients undergoing chemotherapy with doxorubicin and cyclophosphamide.

Objectives: Recent studies suggest that standard dose chemotherapy for breast cancer may cross the blood-brain barrier. However, the evidence for chemotherapy-induced cognitive impairments in breast cancer patients is inconsistent. The purposes of this study in a sample of newly diagnosed patients with breast cancer were to (1) evaluate cognitive function prior to the administration of chemotherapy; (2) assess changes in cognitive function over time; and (3) evaluate potential relationships between cognitive function and anxiety, depression, fatigue, hemoglobin level, menopausal status, and perception of cognitive function.

Methods: Thirty women with breast cancer completed neuropsychological testing before the initiation of chemotherapy and after four cycles of doxorubicin and cyclophosphamide. Descriptive statistics were used to summarize sample characteristics, and paired t-tests were carried out to evaluate for changes in neuropsychological test scores prior to and following completion of chemotherapy. Linear mixed model analyses were used to determine whether significant changes in neuropsychological test scores remained after controlling for anxiety, depression, fatigue, hemoglobin level, menopausal status, and perceived cognitive function.

Results: Significant decreases in visuospatial skill (p<0.001) and total cognitive scores (p=0.001) were found following chemotherapy. In addition, a significant improvement was found in executive function (p=0.014). Of note, these changes remained significant even after controlling for anxiety, depression, fatigue, hemoglobin level, menopausal status, and perceived cognitive function.

Conclusions: Data from this study supported the hypothesis that chemotherapy may have a negative impact on select domains of cognitive function.